Reference: Writing your first WCF Service

The popular ABC’s
This is now becoming popular way to understand how WCF works. A is the address, B the binding and C the contract.

Address is where you communicate. This is not the same as the location you deploy your service, but the URL that will be used internally to map your requests and responses.
Binding is how you communicate. There are several default ones like BasicHttp, TCP, NamedPipes, MSMQ and several others. This is the protocol that the server and client understands while communicating.
Contract is what you communicate. Refer the next section for details on contracts.

There are two types of contracts:
Service Contracts: It is the API the service consumer invokes on your service. It’s the method signature that will go into the WSDL.
Data Contracts: It is your data that would travel from the service consumer and the service. It’s the data structure. This can be found in the schema of your service.

System Service Model
Bindings Section
Binding Class
Custom Binding
Reader Quotas
Reliable Session
Security Mode
Client Credential Type
Proxy Credential Type
Negotiate Service Credential
End Point